ABATTOIRS have reported a rapid increase in live fluke condemnations in recent weeks – but livestock farmers are still being advised to test for the parasite before treating their animals.

Industry groups dedicated to protecting the efficacy of flukicides have stressed that effective treatment depends on properly identifying infection, then timing the chemical response to the right moment in the fluke's life cycle.

In a joint statement, the Sustainable Control of Parasites in Sheep (SCOPS) and Control of Cattle Parasites Sustainably (COWS) groups urged farmers not to dose their stock without first testing them, as there are large variations in fluke numbers between farms and even between areas on individual farms.

Philip Skuce, of the Moredun Research Institute, reported on monitoring work ongoing on Scotland's west coast: “We’ve been sampling sheep on two sentinel farms in Argyll this year. In mid-September about a third of the sheep had positive blood tests, but were still negative on coproantigen and FEC. This gave us an early warning they had been exposed to fluke infection, despite the fluke still being too young to show up on the faecal tests.

"By mid-October 23% were positive on coproantigen and 5% had fluke eggs in the dung. This really underlines how the different tests work over the season. This year it is vital we use testing to guide timing of treatments and flukicide product choice.”

Speaking from Liverpool University, Diana Williams advised: “Testing your sheep for fluke can save money in the long run. We had a case where the poor condition of sheep was assumed to be due to liver fluke but diagnostic testing – blood testing for lambs and dung tests for ewes – showed they were not infected. Avoiding an unnecessary treatment not only saved the farmer a lot of money in terms of flukicide and time, but it also led them to diagnosing the real cause of ill thrift, which improved performance.”

Biobest Laboratories' Rebecca Mearns said: “We’ve been receiving more and more samples for liver fluke testing in recent weeks, and it is clear that using the right test, in the right way, is critical to getting robust results. For the coproantigen Elisa test we are strongly advising farmers to send us individual samples. This is because it has become clear that pooled samples may lead to a false sense of security. A good example is a mid-Wales flock that tested eight individual sheep and only one of the samples was positive. This suggested there were fluke present, but they were still too immature to be detected by this test in all but that one sheep. If the sample had been pooled the positive sheep faeces would be diluted and the overall level been below the level of detection.”

Flock Health Ltd's Fiona Lovatt, addressed the key issue of flukicide efficacy: “I am concerned that while there is evidence of triclabendazole resistance on some farms, many others are jumping to the conclusion that they have resistance without any testing, including making sure the problem is actually liver fluke or carrying out a drench test too early, when the fluke are still immature.”

At Scotland's Rural College, Heather Stevenson agreed: “So far we have seen only a few cases of liver fluke infection from Dumfries and North Cumbria, which means it is very important farmers test before they treat.”